Fattening Pigs on Pasture

Abstract

One of the advantages of keeping growing fattening pigs outside on pasture is that they are more healthy than those indoors (Fishwick, 1935), provided fresh ground, free from parasitic infections, is available. Reviewing American work, Morrison (1936) concluded that faster liveweight gains and improved efficiency of food utilisation are obtained from pigs full-fed on pasture compared with those full-fed in dry lot (also Fishwick, 1935; Smith et al., 1950). Pigs grazing outside in Great Britain usually receive enough sun on their skin to produce sufficient vitamin D to meet their requirements, except in adverse weather (Braude, 1954). Pigs at pasture have access to soil, which is a source of minerals (Davidson, 1930) and of vitamin B12 (Duckworth, 1955). Cunha et al. (1948) found that 5% of soil in a purified pig ration stimulated appetite and increased the haemoglobin value of the blood. Biggar (reported by Boden, 1952) obtained greater liveweight increases from pigs folded on pasture than from those folded on bare soil, showing that herbage is of value in addition to fresh air, sunlight and soil.